Top ten attractions in Nicaragua?

I'd like to know what the best tourist attractions are in Nicaragua? I know that there are some great volcanoes that you can hike up and that Lake Nicaragua is beautiful, but are there any really incredibly places that people would recommend? What are the best things to do in Nicaragua?

Thanks Latin_traveler.
I'm busy doing research on Nicaragua and that is why I posted the question because I thought if it's on a forum then other people would also have access to the answers. I'd love to visit Nicaragua though - it looks like an amazing and beautiful country.
I will look into San Juan Del Sur and the Gran Reserva.
Thanks for your advice.